"But both the leader of the Opposition and the Act Party have indicated they believe I am a suitable person to fulfil that role."
He would also be happy to serve under a different government, if that did happen.
"If at any point my personal views were so far opposed to what I had to represent, then as a matter of integrity you would cease to hold that position. But I don't anticipate that will be a problem with the Government at the moment, or a future government. There's a strong element of bipartisanship in foreign policy. A change in government in New Zealand doesn't mean a wild swing."
Goff did have a word of support for his old parliamentary colleague, Mallard, who left Parliament last week and will start at about the same time as Goff.
"I think Trevor will do a very professional job. He understands what his role is, he has deep experience in New Zealand politics and a strong connection to [Ireland]. I've got no reason to believe he will do anything but a competent and professional job."
Asked about the ever-changing roster of Prime Ministers in the UK – where Rishi Sunak has just replaced Liz Truss – Goff said it was not the place of a diplomat to talk about the internal politics of the country they served in. "But what I would say is the most important thing is that through the interesting period we've had in the last couple of months, while there may have been changes in leaders, there haven't been changes in the policies that are important to New Zealand, such as the free trade agreement and the broad approach to foreign policy."
He said the job was a challenge he was looking forward to at a significant time as that free trade agreement between the two countries kicked into gear, which he expected to be in the near future.
"What makes the UK exciting at the moment is a new, high-standard – some have called it gold-standard – free trade agreement which opens up some new and important opportunities for us to diversify our trade. It creates an opportunity to be an advocate and work alongside the trading organisations that will be keen to expand their trade with the United Kingdom."
He said his former roles as minister of defence, foreign affairs and trade would serve him well in negotiating his way around. He said the defence and security co-operation relationship would also be a big part of the job, especially as the war in Ukraine continued. New Zealand's Defence Force has personnel in the United Kingdom helping with Ukraine's war effort, including training Ukrainian soldiers.
"We are doing that in close partnership with the United Kingdom. That's a significant part of the relationship."
However, he was also looking forward to events such as the coronation of King Charles, which would take place in May. He did not expect to have to contend with a move to become a republic back in New Zealand, saying he did not detect a mood for change.
He had met with King Charles on a visit to New Zealand some years ago "and I think he will be a good King. He was well-briefed, well-informed, engaging." He expected the King would "tone down" his views on issues such as the environment as King, but said he was well ahead of public thinking on that front. "Things he talked about 30 years ago are now accepted norms."
He hoped that the old tradition of the OE to London would recommence in earnest now the borders were reopened – an OE he himself had done in the late 1970s.
"It's an opportunity to live in a big country that shares values with us, that I think is really important to a lot of New Zealanders that are keen to escape the restraints of the Covid pandemic and resume the tradition of spending time in the UK as a platform for other parts of Europe and the world."
Goff said he would have to be more restrained in his views than he was as Mayor - "there are constraints on what you do and say, and that's part of the rules of the game and I absolutely accept that. It won't be a problem for me."
His wife Mary would join him a few months after he started in the role – she would stay in New Zealand for a while to spend more time with a new granddaughter.